The present invention relates to a device for stripping veins, comprising a catheter element which extends in the axial direction from a proximal end to a distal end. The device according to the present invention is suitable for removing veins and in particular is suitable for removing the vena saphena magna. This vena saphena magna is also referred to as VSM.
In man the blood circulation consists of arteries which supply blood and veins which carry blood away. Valves, which act as a non-return valve, are attached to the inside wall of these veins. Every time a person moves his or her body the veins are contracted somewhat by the flexing of the muscles, As a result of this contracting effect the blood is fed via the xe2x80x9cnon-return valvesxe2x80x9d in the direction of the heart.
The venous system in the legs consists of a deep venous system and a surface system In the deep venous system the vena femorales communus in particular is important. In the surface system the VSM and the vena saphena para (VSP) are the most important veins. The surface system is in the subcutaneous fatty tissue.
In medical science it is known that an increase in the diameter of the veins or damage to the valves in the veins results in insufficient functioning of the venous valves. If these valves do not function adequately, the blood pressure in the veins will increase and as a result the veins will expand. Moreover, the veins start to knot and is visible through the skin. This abnormality is also referred to as varicosis or xe2x80x9cvaricose veinsxe2x80x9d.
In order to prevent complications in the case of varicosis the VSM must be removed from the human body. This surgical treatment is also referred to as xe2x80x9cstrippingxe2x80x9d or xe2x80x9cexeresisxe2x80x9d, After the removal or stripping of the VSM the outflow of the venous blood from the legs takes place through the deep venous system. Usually the capacity of the deep venous system is sufficient to ensure a good outflow,
It is possible to remove the entire VSM, from the ankle to the groin. Such a treatment is also referred to as a xe2x80x9clong stripxe2x80x9d. It is also possible to remove part of the VSM, that is to say from the knee to the groin. Such a treatment is also referred to as xe2x80x9cshort strippingxe2x80x9d. Carrying out a so-called short strip usually yields better results and this method is therefore currently standard in medical science. One of the major advantages is that the risk of damage to the nervus saphenus is much lower than in the case of a long strip.
The nervus saphenus nerve runs essentially parallel to We VSM in the leg. This nervus saphenus can become damaged when removing the VSM. Therefore it is advantageous if that section of the VSM from the knee to the ankle remains behind in the leg.
In the state of the art it is customary to remove the VSM with the aid of a catheter. This catheter is also referred to as the xe2x80x9cstripperxe2x80x9d. This catheter is formed by a long, in, flexible element that is introduced into the VSM from the groin. To this end an initial incision is made in the skin at the location of the groin. The catheter is inserted in the VSM until the distal end reaches the knee. A second incision is made at the location of the knee and the VSM, with. the distal end of the catheter therein, is partially pulled out of the body. The lower section, or the supplying section of the VSM, is ligated. That is to say: closed off by knotting with for example, a wire and left behind in the leg. The upper section of the VSM, or the discharging section, that runs from the knee to the groin is attached to the catheter with the aid of a ligature or a wire. A cap, the so-called strip head, is then fitted on the end of the catheter, which cap ensures that the catheter Yes a relatively broad cross-section close to the end.
The catheter is then pulled out of the human body from the groin end, During this operation the VSM is removed from the body with the catheter. During this operation the cap fitted on the end of the catheter serves as a stop which ensures that the VSM is pushed forward from the knee end in the direction of the groin.
This known method and the instruments used for this method have a number of disadvantages. Firstly, an incision has to be made at the location of the knee. This incision must be sufficiently large for the cap which is fitted on the end of the catheter to be inserted through the opening. For proper operation of the stop function the cap usually has a diameter of 12-16 mm. This means that the incision has to be made relatively large. Many patients find it a disadvantage from the cosmetic standpoint that a scar will remain on the leg at the location of the knee. Secondly, it is disadvantageous that the cap which is fitted on the end of the catheter acts as a propulsion element. The VSM will accumulate as a plug in front of the cap when the catheter is pulled out of the human body. This plug will become increasingly large as the end of the catheter approaches the groin, This means that a relatively wide subcutaneous channel is drawn through the patient""s thigh. This wide channel can cause internal damage and complications. Finally, searching for, exposing and tying off the VSM at the location of the knee increases the risk of injury to the nervus saphenus.
The aim of the present invention is to provide a device with the aid of which a vein, and in particular the section of the VSM, can be removed from the human body, the device being designed such that it is not necessary to make an incision in the skin at the location of the knee. What must be achieved t this device is that the channel rains behind in the leg after removal of the VSM, or the subcutaneous channel, is as small as possible.
Said aim is achieved in the present invention in that the distal end is provided with cutting means, with cutting elements, which are movable between a first or neutral position, in which the cutting elements extend essentially in the axial direction of the catheter element, and a second or working position, in which the cutting elements are directed outwards with respect to the catheter element.
With the aid of the device according to the present invention it is possible to allow the cutting elements to act endovascularly (from the inside of the venous vessel) on the vein wall. This means that the second incision, which generally speaking was needed to search for and cut through the VSM, becomes superfluous.
According to the present invention it is advantageous that the catheter element is provided with guide means for guiding the cutting elements from the first position into the second position.
In this context it is possible that the cutting means comprise a base body that is slidably attached to the catheter element, the cutting elements being hingeably connected to said base body. In this context it is advantageous that the guide means are formed by a thickening at the distal end of the catheter element, it being possible to move the base body from the first position in the axial direction to the distal end of the catheter element into the second position, the thickening being forced between the cutting elements during this movement the various features being such that in the second position the cutting elements are directed essentially outwards with respect to the catheter element.
In practice it will be possible to move the catheter, at the distal end thereof provided with the cutting elements, backwards in the VSM from the groin to the knee, The VSM can then be joined to the catheter inserted in the VSM with the aid of a subcutaneous ligature. This join is produced with the aid of a loop made in the life. This ligature is deliberately kept relatively long and positioned on the groin side of the cutting elements.
Traction or tensile force can then be exerted on the catheter, whilst the cutting elements are essentially held in place in the VSM. The cutting elements are held in place by exert traction in the opposite direction with the aid of the Ligature. What is achieved by this means is that the cutting element is moved from the first, neutral position into the cutting position. In said cutting position the cutting elements will at least partially weaken the wall of the VSM from the inside, for example by partially cutting tough or perforating the wall.
Furthermore, it is possible for the cutting means to be arranged such that they are movable in the axial direction towards the distal end of the catheter element from the second position into a third position, wherein in the third position the thickening is taken up in a space which is enclosed by the cutting elements and the base body, respectively. By applying further traction in the direction of the di end of the catheter element with the aid of the ligature, the cutting elements can be brought into a second neutral position. In said second neutral position the cutting elements will again extend essentially in the axial direction along the catheter element. On further traction, the VSM will tear off at the location of the perforations or cuts made. The upper section of the VSM will be removed from the leg with the catheter, The lower section, or supplying section, of the VSM is not tied off but is taken care of by external compression.
Reference has been made above to traction which is exerted with the aid of the catheter, whilst traction in the opposing direction is exerted with the aid of the ligature. The same effect can, of course, also be achieved by using the ligature as a stop, traction being exerted solely with the aid of the catheter.
Because the catheter according to the present invention will have a relatively small diameter, even when the cutting element has been fixed to the distal end, it is possible to remove the VSM by invagination. In this procedure the lumen of the VSM is used as guide channel The vessel is turned inside out during the removal thereof.
A relatively long ligature is used when attaching the wall of the vein to the catheter, at the location of the cutting element. During removal of the catheter this ligature can be used to exert traction on the distal end of the catheter element, which traction is in the opposite direction to the traction on the catheter element itself. Because the traction on the catheter element and the counter-traction can be regulated well, the catheter can be pulled out of the human body in a controlled manner.
According to a further embodiment it is possible for the guide means to be formed by auxiliary arms which are hingeably joined at one end to the distal end of the cutting elements and at the other end to the distal end of the catheter element. With the aid of the relatively long wire the cutting elements can again be moved from a first neutral position via a cutting position into a second neutral position, guiding of the cutting elements being carried out by the auxiliary arms.
According to a further embodiment it is possible to construct the catheter element with two bodies. With this arrangement it is possible for the catheter element to comprise an inner catheter body and an outer catheter body arranged around the inner body, wherein the inner catheter body is movable in the axial direction with respect to the outer catheter body, whilst the inner catheter body is provided at the distal end thereof with one or more cutting elements, and wherein the outer catheter body is provided at the distal end thereof with guide means, and the inner body is movable relative to the outer body from a first position in which the cutting elements are essentially enclosed by the guide means into a second position in which the cutting elements have been moved essentially in the radial direction out of the guide means.
It is also possible for the catheter element to be provided at the end thereof with one or more cutting elements, wherein said cutting elements are mounted on either side of or on an inflatable body, the various features being such that the cutting elements can be moved radially outwards by inflating the inflatable element.
For the device according to the present invention to function well it is advantageous that the device has a length of preferably 600 to 1000 mm, :more particularly of 600 to 750 mm and more preferentially of 600 to 700 mm.
Use of the device according to the present invention has a number of advantages. Firstly, the number of actions tat have to be performed in order to remove the upper section of the VSM is relatively limited. This means that the operation can be carried out quickly and that the operating theatre facilities can be better utilized Secondly, the number of disposable instruments is limited because the distal incision at the location of the knee, ligating the VSM and closing the distal incision become superfluous.
In view of the abovementioned advantages, it is advantageous for the device according to the present invention to be packed as a kit.
It is possible for a kit comprising the installation according to the invention and a surgical wire, which is provided at the end thereof with a prefitted cutting needle, to be packed sterile as a whole in a container. It is possible for the kit also to contain a surgical knife. In this context it is possible for the surgical wire to have a length of 1000 to 1600 mm, preferably 1200 to 1400 mm and most preferentially 1300 mm.
Sterile packaging of the abovementioned kit has the advantage that operating theatre logistics can be simplified appreciably.